We will not attempt to relate couplings of different dimensionality to each other either. This problem was recently analyzed in Ref. [1]}, [2]}, [3]} and the expected dimensional-analysis scaling of various couplings with order \(\mathcal {O}(1)\)  coefficients was rigorously established. It would be very interesting to apply these techniques to the gravitational amplitudes discussed here but we defer this to the future.
